On 10/25/2006 2:35 PM, Joe Flowers wrote: > If I pre-pend a message's Envelope to it's Body, can Spamassassin do > anything useful with it?
At a minimum you can use the envelope recipient(s) to do some kinds of spam-trap filtering (eg, is the message addressed to a spamtrap and me). You can use the envelope sender to do some kinds of whitelisting too (such as whitelisting your aunt at yahoo even if the you have the whole yahoo domain otherwise blacklisted, or whitelisting a mailing list "sender"). My LDAPfilter plugin (http://www.ehsco.com/misc/ldapfilter/) uses them for these kinds of purposes. Other possibilities exist too. Envelope sender can be used for some SPF filters that aren't currently done, for example. The first problem is that there is no standard header field, and in the case of envelope recipient(s) where there can be multiple entries, there is no standard for the field data. I use X-Envelope-To and X-Envelope-From with typical RFC822 address syntaxes (no "real name" blob, etc), but only because I had nothing else to use and that structure seems to be the most obvious and least harmful. Another consideration is that they have to be created by the MTA, and spamassassin doesn't have possession of the envelope data so it can't create them. In my case I have to make postfix generate them in order for them to be usable, and the LDAPfilter plugin has .cf options that point to the header fields in questions (eg, "ldapfilter_env_from_header") But yeah, if they are provided and if there is a way to tell spamassassin where to look, they are very useful. -- Eric A. Hall http://www.ehsco.com/ Internet Core Protocols http://www.oreilly.com/catalog/coreprot/
